Worn Bearing Seats and Seal Areas
A bearing spinning on the shaft, fretting and seal friction cause dimensional loss on critical diameters. Instead of waiting for a new shaft, it can be brought back to original tolerance by build-up, coating and precision grinding.
Symptoms
- Loose bearing seat, bearing spinning on the shaft, discolouration
- Grooves, scratches and leakage at the seal / packing area
- Rust-coloured fretting powder
- Increasing runout, vibration and repeated bearing failures
Typical Parts
Loss of interference fit, assembly errors, vibration and lubrication problems create micro-movement (fretting) at the bearing seat; in the seal area continuous friction and particles cut grooves. As the loss grows, failures become more frequent and the housing is damaged too.
Which Process for Which Case?
The choice depends on how many millimetres were lost, the load and the final tolerance. In every case the last step is precision grinding and a measurement report.
| Solution | Material System | Typical Thickness | When Is It the Right Choice? |
|---|---|---|---|
| HVOF + grinding | WC-CoCr, Cr₃C₂-NiCr, Ni-based | ~0.1–0.8 mm on diameter | Small losses; wear-resistant, tight-tolerance surface (seal areas, sealing zones) |
| Arc spray + machining | Stainless / Ni-based wires | ~0.5–2 mm on diameter | Medium losses; economical restoration of large diameters |
| Weld build-up + machining | Filler matched to base material | By loss (mm) | Large losses, grooves and broken zones; load-bearing sections |
| Weld build-up + HVOF | Build-up + carbide coating | Combined | Large dimensional loss plus the need for wear resistance |
Values are typical ranges; the final choice is made after the part, base material and operating conditions have been seen.
Restoring the bearing seat does not remove the cause of failure
If the bearing seat on the same shaft keeps getting loose, there may be housing ovality, misalignment or a wrong fit tolerance. When the shaft arrives we measure and report all diameters and runout; we recommend checking the housing too. If the weldability of the base material is uncertain, we prefer the weld-free (thermal spray) route.
FAQ
Can a worn shaft be reused instead of making a new one?
In most cases, yes. The worn diameter is built up by coating or welding, then precision ground to the required tolerance and surface roughness, and delivered with a measurement report.
Is thermal spray safe on a bearing seat?
With the right thickness and material it is a widely used method. For losses beyond the thickness limit, weld build-up is preferred.
What shaft sizes do you repair?
For coating, parts up to 7 m long and Ø1,600 mm diameter with no weight limit; for machining up to Ø1,250 mm diameter and 4 m length in our workshop. Details on the capabilities page.
Let’s Talk About Your Part
Take a photo of the damaged area and send it by e-mail or WhatsApp, or call us directly. On the phone we identify the mechanism together and give a suitable process and a rough cost/lead-time indication in the same call.
- Close-up and overall photo of the damaged area
- Diameter / length or a technical drawing
- Operating conditions: temperature, medium, particles, speed